For optically connecting optical components to optical waveguides, coupling devices of a very precise construction are required. If the coupling device must be of a detachable type, so that an optical component can be coupled to different optical waveguides or an optical waveguide to different optical components, then a plug-and-socket connection is very efficient. The parts thereof must also be of a very precise structure, to ensure tht on the one hand the coupling losses can be reduced to a minimum and on the other hand no differences in the degree of coupling occur when several coupling device portions are coupled to each other. To that end it is a requirement for the distance of the optical waveguide front face from the surface of the optical component to be accurately equal to the best possible extent for all the parts of the coupling device.